rowland



(No Model.) 2 Sheets-Sheet 1..

' O. ROWLAND.

CALCULATING DEVICE.

No. 284,576. Patented Sept. 4, 1883.

(No Model.) 2 Sheets-Sheet 2.

G. ROWLAND.

CALCULATING DEVICE.

No. 284,576. Patented Sept. 4, 1883.

N. PEYERS. mmumw WW0". n. c

UNITED STATES PATENT OFFICE.

CHARLES RO\VL'AXD, OF Q'UlNCY, ILLINOIS.

CALCULATING DEVICE.

SPECIFICATION forming part of Letters Patent No. 284,576, dated September 4, 1883.

Application filed July 16, 1883.

Be it known that 1, CHARLES ROWLAND, of Quincy, in the county of Adams and State of lllinois, have invented a new and useful Improvement in Calculating Devices; and I. do hereby declare that the following is a full and exact description. of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

My invention relates to that class of devices known as calculating devices, and the ob ject I have in view is to provide a simple and convenient device of this character by means of which the fundamental rules of arithmeticas addition, subtraction, multiplication, and division-may be taught with great facility, and the learner enabled by its use to become thoroughly conversant with the table of each rule in a comparatively short period of time.

\Vith these ends in view the invention consists in the features of construction and the arrangement and adaptation of parts, as will be more fully hereinafter set forth, and specifically pointed out in the claims.

To enable others to understand how to construct and operate my device, I. will now proceed to describe the same with reference to the accompanying drawings, which form a part of this specification, and in which- Figure 1 is a plan view of the reverse side of the device, showing the arrangement and adaptation of parts for multiplying numbers. Fig. 2 is a similar view of the obverse side, showing the adaptation of parts for dividing numbers. Fig. 3 is a plan view of the reverse side of the device, showing the adaptation of parts when designed for adding numbers; and Fig. t is a similar view of the obverse side, showing the arrangement of parts when de signed for subtracting numbers.

Similar letters of reference denote like parts throughout all the views.

In the drawings, A represents a circular plate or disk, which. is provided with a bifurcated. handle, 13, the bifurcated parts, as b, extending to the center of the disk, at which point the latter is pivotally secured thereto, and thereby adapted to be rotated between said parts I) as occasion requires in operating the device.

G and 0 represent the reverse and. obverse sides, respectively, of the disk. The surface (X0 model.)

of each side in divided into thirty-six equal parts by means of the radial lines (1, said lines extending from the periphery of the disk to points equidistant from its center. Then by means of curvedlines the inner ends of the ra dial lines are connected in such manner as to have three of the said lines connected, and then,leaving the contiguous lines unconnected, have the three next lines connected, and so on in that orderfor the entire number of lines. The spaces within the connected lines a are then subdivided into twelve equal partsor spaces by means of curved lines drawn parallel with the curved lines that connect the inner ends of the said lines a. The curved lines are represented by the letter a in the drawings.

From the above description, taken in connection with the drawings, it will be observed that the faces orsides of the disk are each provided with a series of twelve similar groups of lines, each group comprising three of the radial lines a and twelve of the curved lines a, and being divided thereby into two radial columns of twelve transverse spaces each.

It will be further observed that between each group of the lines (I and a there is a radial space, (represented by letter D,) in which no lines a appear.

The outer surfaces of the parts I) of handle B are divided by a series of transverse lines into twelve spaces, said spaces corresponding in width to those formed by curved lines a, so that by rotating disk A until any one of the radial spaces D is covered by the part b the lines and spaces upon its surface and those formed by the curved lines a, contiguous therewith, may coincide. The spaces upon the handle are numbered from one to twelve, beginning with the space nearest the center of the disk and ending with the last space near its periphery. ,4

For adapting the device to multiplying numbers, the reverse side 0 of the disk is provided with the arrangement of figures as shown in Fig. l of the drawings. By consulting said figure, it will be seen that the nu 1n bers to be multiplied are arranged in the spaces of the radial columns at the left of the radial spaces D, said numbers running, respectively, from one to twelve around the face of the disk from left to right, while in the spaces of the radial columns at the right of said spaces D are arranged the numbers representing the respective products of those numbers when multiplied by the figures upon handle B. The table is completed by printing the word is above the line of products of the number 1, the word are above the products of the other lines of numbers, and the word times above the number on handle B.

For adapting the device to dividing numbers, the figures are arranged as shown in 'Fig. 2 of the drawings. Here the numbers to be divided occupy the spaces of the radial columns at the left of the radial spaces D, and the dividing numbers or divisors the spaces of the radial columns tothe left of these columns, while the quotient, or the number of .multiplied and their products.

times one set of figures is contained in the other, is represented, respectively, by the numbers upon handle B. Vith this distinction the arrangement of the figures is the same as that for multiplying. The table is completed by printing word into above the lines of numbers to be divided, and word times above the numbers on handle B.

For adding numbers, the figures are an ranged'as shown in Fig. 3 of the drawings. Here the numbers to be added, with their respcctive amounts, are arranged in substantially the same manner as in the table for multiplying, while the numbers on handle B rep.- resent the numbers which are added to the figures in the radial columns at the left side of spaces D. The table is completed by printing word make above eachline of amounts, and word and above the figures on handle B.

For subtractingnumbers, the figures are arranged as shown in Fig. 4 of the drawings. Here the numbers to be substracted are arranged in substantially the same manner as in the table for dividing, while the numbers on the handle represent, respectively, the difference between any two sets of figures in the radial columns at the left of radial spaces D, heretofore referred to. The table is completed by printing word from above the radial columns just to the left of spaces D, and the word leaves above the figures on. han

dle B.

The operation of the device is as follows: If it is desired to use the multiplication table and to find any one of the twelve tablesas, for instance, the table of fives-the device is held by handle B and the disk A rotated until the column of fives is just at the left of thenumbers upon the handle, and the part b of the latter occupies the radial space D, and is thus brought between the numbers to be If it is desired to use the division-table, the disk is rotated until the handle occupies the radial space to the right of the columns of numbers which it is desired to divide, the figures upon the handle in this instance showing the num ber of times the respective divisor is contained in the number desired to be divided.

In the addition and subtraction tables the operations of the device are substantially the same as for multiplying and dividing, respectively.

While I prefer to make the calculating device in sets of two each, so that one will serve for adding and subtracting numbers and the tions as to the details of form and construction may be resorted to without departing from my invention. For instance, the rotating disk might besecured to the handle by means of a spring or clamp pivot, so as to allow ready re movaltherefrom, and thus the one handle be utilized for the whole number of disks. in a. set. Again, the lines-by which the disk and handle are divided into the number-containing spaces might be omitted, and only the numbers with which calculations are to be made appear, their relative arrangement upon the disk and handle ofcourse being the same as in the first instance. Again, the periphery of the disk might be flanged, and its reverse and obverse faces provided with removable paper. or cardboard plates, upon which appear the desired lines and numbers for any one of the tables. A gain, the disk and handle might be divided into more than twelve number containing spaces, and thus the device be adapted to make calculations with numbers of higher denominations. Hence I do not limit myself to the pre cise construction shown and described, but

reserve to myself the right to make all such changesv and alterations as may properly fall within the scope of my invention.

- Having thus described my invention, what I claim is v 1. In a device for calculating numbers, the combination, with a circular disk having upon its reverse side a series of radial spaces, with radial columns to the left and right of the radial spaces, the columns at the left containing the numbers with which calculations are to be made, and those at the right the numbers representing, respectively, the results of such calculations, of a handle providedwith bifurcated parts, between which the disk is centrall-y pivoted, and having a column of figures arranged,

' as shown, for making calculations with the columns of numbers at the left of any of the radial spaces upon the disk, accordingly as the latter is rotated to bring said numbers and figures in juxtaposition, all substantially as set forth.

I 2. In a device for calculating numbers, the combination, with a circular disk having upon its obverse side a series of radial spaces, with two radial columns at the left of the radial spaces,,the columns containing, respectively, the numbers with and by which calculations are to be made, of a handle provided with bifurcated parts, between which the disk is centrally pivoted, and having a column of figures arranged, as shown, for representing the results, respectively, of the calculations between' the said columns of numbers at the left of any,

of the radial spaces upon the disk, accordingly as the latter is rotated to bring said numbers and figures in juxtaposition, all substantially as set forth.

3. In a device for calculating numbers, the combination, with a circular disk having upon its reverse side a series of radial spaces, with radial columns to the left and right of the radial spaces, the columns at the left containing the numbers with which calculations are to be made, and those at the right the numbers representing, respectively, the results of the calculations, and having a similar series of radial spaces upon its obverse side, with two radial columns at the left of said radial spaces, the columns containing, respectively, the numbers with and by which calculations are to be made,

of a handle provided with bifurcated parts, be tween which the disk is centrally pivoted, and having upon its reverse and obverse sides a similar column of figures, arranged as shown, the figures upon the reverse sidebeingdesigned numbers at the left of any the radial spaces upon the reverse side of the disk, and those upon the obverse side of the handle for representing the results, respectively, of the calculations between the columns of numbers at the left of any the radial spaces upon the obverse side of said disk, accordingly as the latter is rotated to bring said numbers and figures in juxtaposition, all substantially as set forth.

This specification signed and witnessed this 16th day of July, 1883.

CHARLES ROlVLA ND.

Witnesses:

L. C. YOUNG, TM. M SMITH.

for making calculations with the columns of 

